It is underway now, and being streamed from the New Hampshire Secretary of State website.
Mostly we see the opening of sealed scanners. I have no idea where this will go.
The audit is happening because of the following sequence:
1. The election resulted in Republicans winning all four state legislature seats;
2. The fifth place finisher, a Democrat, asked for a recount;
3. The recount showed the Republicans getting about 300 more votes each, and the Democrat about 100 fewer votes. The raw numbers are probably not suspicious, but the change from count to recount is quite a bit higher than we usually see.